“NCIS” STAR HARMON’S ALL HEART!

for bighearted “NCIS” star MARK HARMON, who rallied to help a hair/makeup lady who’s worked on the show for years and was suddenly struck down by breast cancer – and staggering medical bills.

“Mark asked the cast and crew for donations, and wound up collecting close to $9,000,” said an “NCIS” source

. “Good Samaritan Mark then matched what was donated and – on a visit to the gal’s bedside at Cedars-Sinai hospital – brought her a big basket of goodies, a huge card signed by everyone on the cast and crew, plus a check for $18,000!”